Use of ethylcellulose polymers as stabilizer in fat-based food suspensions examined on the example of model reduced-fat chocolate

Surfactants are an important ingredient in the manufacture of chocolate. Their role is to coat the surfaces of the sugar and cocoa particles dispersed in fat, generally cocoa butter, to maintain or enhance the flowability of molten chocolate. Coating the surfaces of the dispersed particles with a surfactant reduces inter-particle interactions responsible for particle aggregation which leads to viscosity reduction of the mixture. Controlled flow behavior of molten chocolate is a requirement for successful processing and for optimal mouthfeel. This becomes in particular crucial in the formulation of fat-reduced chocolate. In fat-reduced chocolate, low molecular weight surfactants such as lecithin and polyglycerol polyricinoleate (PGPR) need to be applied at unacceptably high concentrations to maintain flowability of a chocolate with increased dispersed phase volume. This paper reports on an alternative approach, the use of the polymeric surfactant ethylcellulose. Shear viscosity measurements on model chocolates demonstrated a viscosity reducing effect. The effect of ethylcellulose polymer adsorbed at an oil/water interface was visualized in volume change experiments on macroscopic pendant drops revealing a difference in the nature of the interface compared to an interface covered with a low molecular weight surfactant.